grub-pc versus grub-efi-amd64

[Tom H]

On Tue, Sep 1, 2020 at 2:19 PM Volker Wysk <post at volker-wysk.de> wrote:
> Am Montag, den 31.08.2020, 20:57 +0200 schrieb Tom H:
>> On Mon, Aug 31, 2020 at 7:02 PM Volker Wysk <post at volker-wysk.de>
>> wrote:
>>> Am Montag, den 31.08.2020, 14:27 +0200 schrieb Tom H:
>>>> On Sat, Aug 29, 2020 at 5:31 PM Volker Wysk <post at volker-wysk.de>
>>>> wrote:


>>>> I installed 20.10 right after 20.04 was released on an EFI
>>>> system, and I also have "grub-pc" rather than "grub-efi-amd64"
>>>> installed.
>>>
>>> And this isn't a packaging bug...
>>
>> I don't think so. I _feel_ that it's more likely to be an apt bug.
>
> So you *do* think that it's a bug - that grub-efi-amd64 should be
> installed rather than grub-pc.

It looks like an esoteric apt resolver bug, but not a packaging bug.


> And installing grub-efi-amd64, to replace grub-pc, really really
> won't break the system..? I'm hesitant...  :)
>
> There is quite something happening when doing it:
>
> -----snip-----
> desktop ~ % apt --simulate install grub-efi-amd64
> (...)
> Inst grub2-common [2.04-1ubuntu26.2] (2.04-1ubuntu26.3
> Ubuntu:20.04/focal-updates [amd64]) [grub-pc:amd64 ]
> Remv grub-pc [2.04-1ubuntu26.2] [grub-gfxpayload-lists:amd64 grub-efi-
> amd64-signed:amd64 ]
> Inst grub-efi-amd64 (2.04-1ubuntu26.3 Ubuntu:20.04/focal-updates
> [amd64]) [grub-gfxpayload-lists:amd64 ]
> Remv grub-gfxpayload-lists [0.7] []
> Inst grub-pc-bin [2.04-1ubuntu26.2] (2.04-1ubuntu26.3
> Ubuntu:20.04/focal-updates [amd64]) []
> Inst grub-efi-amd64-signed [1.142.4+2.04-1ubuntu26.2] (1.142.5+2.04-
> 1ubuntu26.3 Ubuntu:20.04/focal-updates [amd64]) []
> Inst grub-efi-amd64-bin [2.04-1ubuntu26.2] (2.04-1ubuntu26.3
> Ubuntu:20.04/focal-updates [amd64]) []
> Inst grub-common [2.04-1ubuntu26.2] (2.04-1ubuntu26.3
> Ubuntu:20.04/focal-updates [amd64])
> Conf grub2-common (2.04-1ubuntu26.3 Ubuntu:20.04/focal-updates [amd64])
> Conf grub-efi-amd64 (2.04-1ubuntu26.3 Ubuntu:20.04/focal-updates
> [amd64])
> Conf grub-pc-bin (2.04-1ubuntu26.3 Ubuntu:20.04/focal-updates [amd64])
> Conf grub-efi-amd64-signed (1.142.5+2.04-1ubuntu26.3
> Ubuntu:20.04/focal-updates [amd64])
> Conf grub-efi-amd64-bin (2.04-1ubuntu26.3 Ubuntu:20.04/focal-updates
> [amd64])
> Conf grub-common (2.04-1ubuntu26.3 Ubuntu:20.04/focal-updates [amd64])
> -----snip-----

You have a very different installation from mine.

How can you not have "grub2-common" already installed? What's the
output of "which grub-install"?

I don't understand why "grub-pc-bin" is installed alongside
"grub-efi-amd64" and when "grub-pc" is being removed, but it's too
late to go through the dependencies and figure it out...


>>> What disturbs me, is that the "update-grub" script is in the
>>> "grub-pc" package, but not in "grub-efi-amd64". Isn't this script
>>> needed, for instance, when a new kernel is to be installed?
>>
>> "update-grub" in "grub-pc" is the legacy "update-grub" script, which
>> means that it is "update-grub" of grub1. Running grub1's "update-
>> grub"
>> would update "/boot/grub/menu.lst" in between "BEGIN AUTOMAGIC
>> KERNELS
>> LIST" and "END DEBIAN AUTOMAGIC KERNELS LIST" lines.
>
> Does that mean that "update-grub" is obsolete? I recall vaguely that
> it used to be executed whenever a new kernel gets installed. Is this
> no longer the case with Grub2?

grub2's update-grub is "/usr/sbin/update-grub".